A person owns shares in a small company that announces bad news before the open. The stock drops to a level marked on the screen, and then it stops. There are sellers everywhere and no buyers, the price is frozen, and the sell button does nothing.
They are learning about circuit limits the way most people do, which is at the exact moment one traps them.
This post is about why prices are not allowed to move freely, what happens when they hit the edge, and the uncomfortable truth that the mechanism designed to protect you is sometimes the reason you cannot get out.
Two different things with similar names
People use circuit to mean two separate mechanisms. They work differently and it is worth keeping them apart.
A price band applies to a single stock. It is the maximum that one share is allowed to move in a day, up or down, from the previous close.
A market wide circuit breaker applies to everything at once. It halts the entire market when a benchmark index moves too far in a day.
One freezes a stock. The other stops the country. Most days you will only ever meet the first.
Price bands on a single stock
Every stock in the cash market has a daily price band set by the exchange. On NSE the bands are 2, 5, 10 or 20 per cent, either way, from the previous close. Stocks that have derivative contracts have no fixed band of this kind (more on that below). The 20 per cent band is the default for all remaining securities, including debentures and preference shares.
The tighter bands, 2, 5 and 10 per cent, are placed on individual securities by the exchange, which is why the smallest and thinnest stocks are the ones most often caught by them. A band that narrow stops a single determined participant from sending a stock anywhere.
When a stock reaches the top of its band it is at its upper circuit. When it reaches the bottom it is at its lower circuit.
Here is the part that catches people, and it is the whole reason this post exists.
At the lower limit, sellers can have orders queued at the permitted price but, without sufficient opposing buy demand, those orders do not execute.
Likewise, at the upper limit, buy orders can be entered but remain unexecuted when there is no matching sell liquidity.
A circuit does not gently slow a stock down. It stops it dead, and it stops it in the direction that is worst for whoever is on the wrong side.
Why you can be completely stuck
The lower circuit is the one that hurts, so it is worth being blunt about it.
If a stock is locked at its lower circuit, your sell order is valid, it is sitting in the queue, and it will not execute because there is no buyer. The stock can stay there all day. It can open at the lower circuit again the next day, and the day after. People have watched a holding fall by the daily limit for several consecutive sessions without ever being able to sell a single share.
This is not a fault, and it is not your broker. It is the mechanism working exactly as designed. The design protects the market from disorderly collapse. It does not protect you from being on the wrong side of one.
A stop loss, incidentally, does nothing here. It triggers, it sends a sell order, and that order joins the same queue as everyone else’s, unfilled.
The stocks with no ordinary circuit
Stocks that have futures and options contracts do not get a fixed daily band in the same way as other stocks. The reasoning is that the derivatives market provides continuous price discovery, so the stock can be left freer to move.
A stock with no derivatives of its own can still be subject to price bands if it is part of an index on which derivatives trade.
That is why you will sometimes see an F&O stock fall thirty or forty per cent in a session when an ordinary stock cannot fall more than twenty. The protection that stops smaller stocks does not apply to them in the same way.
This does not mean that these stocks are genuinely unlimited. They operate under a dynamic price-band mechanism that can be widened in stages, with a cooling-off period between stages. This allows a large move to happen progressively rather than in one jump. SEBI has also been reported to be consulting on applying dynamic price bands uniformly across exchanges for these stocks. That is a proposal, not the current rule.
The practical point for now is that the largest, most liquid stocks can move much further in a day than the daily-band stocks, which is the opposite of what most beginners assume.
The market wide circuit breaker
This is the big one, and it is rare.
If the Nifty 50 or the Sensex, whichever breaches first, moves 10, 15 or 20 per cent from the previous close, trading halts across the entire market, cash and derivatives together. It applies symmetrically, to a crash or a surge.
The halt gets longer the more severe the move and the earlier in the day it happens. A ten per cent fall in the morning pauses the market for longer than the same fall in the afternoon. After the pause, trading restarts with a pre-open call auction to find a fresh price rather than resuming mid-panic.
The twenty per cent level closes the market for the rest of the day.
The whole mechanism has fired only a handful of times, and the occasions are worth knowing because they tell you what it takes. An unexpected general election result in 2004, which hit two levels in a single day. The global financial crisis in 2008. And the pandemic crash of March 2020, the most recent, which halted trading for forty five minutes.
The limits are recalculated every day from the previous close and published each morning by both exchanges, so the point at which they would trigger moves with the market and is knowable in advance.
What this means for you
Do not treat a locked circuit as a price. A stock frozen at its upper circuit is not worth that price to you, because you cannot buy it there. A stock at its lower circuit is not something you can exit at that number. The screen shows a price at which nothing is trading.
Chasing repeated upper circuits can leave investors exposed to a sharp reversal. A small stock hitting repeated upper circuits looks like a rocket and feels like a missed opportunity. The same illiquidity that drives it up in a queue of unfilled buy orders will lock it at the lower circuit just as completely when the mood turns, and then the queue is on the other side and you are in it.
Illiquidity is the common thread. Wide beginner losses in small stocks are rarely about the circuit rule itself. They are about owning something that only moves in locked circuits, up or down, with no ordinary trading in between. The circuit did not cause that. It revealed it.
Common questions
What is a circuit limit?
The maximum a stock’s price is allowed to move in a single day, up or down, from its previous close. Reaching it halts trading in that stock at that price.
What is the difference between upper and lower circuit?
Upper circuit is the daily ceiling, where buyers are queued but there are no sellers at the permitted price. Lower circuit is the floor, where sellers are queued but there are no buyers, which is why you cannot sell a stock locked there.
Why can I not sell a stock at its lower circuit?
Because at the lower circuit everyone wants to sell and there are no buyers. Your order is valid but sits unfilled until a buyer appears, which may not happen that day.
Do all stocks have circuit limits?
Most do. Cash market stocks have daily bands of 2, 5, 10 or 20 per cent, with 20 per cent as the default. Stocks with derivative contracts have no fixed band and instead operate under a dynamic mechanism that can allow much larger moves in a day.
What is a market wide circuit breaker?
A halt of the whole market when the Nifty or Sensex moves 10, 15 or 20 per cent from the previous close. It is designed to pause trading during an unusually sharp market-wide move and give participants time to reassess.
Does a stop loss work if a stock hits its circuit?
No. The stop loss triggers and sends a sell order, but if the stock is locked at its lower circuit there is no buyer, so the order sits unfilled like every other.
How often does the whole market halt?
Very rarely. It has happened only a handful of times since 2001, most recently in March 2020. The 20 per cent level has never been reached.
The short version
A circuit limit caps how far a price can travel in a day, and freezes it there when it arrives. At the lower circuit that freeze can trap you in a falling stock with no way out, which is the risk worth understanding before you own anything small or thinly traded.
The screen still shows a price. Whether you can actually trade at it is a different question, and the circuit is the reason the two come apart.
Risk disclosure
Hem Finlease Private Limited, SEBI Registration No. INZ000167734. Hem Securities Limited, SEBI Reg. No. IN-DP-568-2021, CDSL: 17700/17701.
Investments in the securities market are subject to market risks. Read all the related documents carefully before investing. Registration granted by SEBI and membership of recognised stock exchanges do not guarantee the performance of the intermediary or provide any assurance of returns to investors.
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